The present disclosure relates to railroad tank cars and in particular relates to attachment of stub sills to the ends of the tank of such a car.
Railway tank cars may be used for carrying a variety of liquid, gaseous, and semi-liquid ladings. Such railway tank cars often include a horizontal, generally cylindrical tank. For many such tank cars, the tank not only carries the lading, but is also used as a primary structural member to carry longitudinal train loads.
These cars typically have stub center sills on each end of the car along with transverse bolster assemblies. The sills carry couplers at their outer ends, and the bolsters have truck assemblies pivotally connected thereto to support the ends of the tank car on the railway tracks. Saddle assemblies, combined with the bolster assemblies, are typically provided at each end of the car. The saddle assembly usually is mated with a doubler plate or saddle pad that is attached to the tank. The saddle pad is typically of steel plate construction and conformed to fit onto the adjacent outer surface of the cylindrical tank.
Each end of the tank typically has a convex head and a doubler plate or head pad of steel plate. In securing the stub center sill to the tank a head brace, typically a U-shaped, wedge-like piece, is placed between the head pad and portions of the stub center sill. It has been conventional to weld the head brace into place, but such welds have been subject to a significant number of fatigue cracks on the head braces or the weld joints associated with the head braces.